Caliper gauge



W. AMES CALIPER GAUGE July 6 1926.

Filed March 26 s il .finlll ,llllllll Patented July 6, 1926.

UNITED STATES PATENT o'FFiCm WARREN Anas, or wALTHA-n, MASSACHUSETTS; AssIeNon To E. C. AMES' Co.. on' y wALTnAnr-, mAssACHUsETTs, A CoaroaATIoN or n AssACHUsETTs.

CAEIPEE GAUGE. l

' Application lled Iarch, 1924. Serial Il'o. '101,398'.l

My invention relates to calipering instru-v ments and particularly but not exclusively to one for calipering the inside diameters of.

l cylindrical surfaces.

My invention will be best understood from theA following description' when read in the' light of the accompany-ing drawings of one -speciic embodiment of my invention selected -forillustrative pur oses, while the xscope of my linvention wil be more particularly l pointed out. in the appended claims.

1w to cylindrical surfaces of various-dameters;'

' 1. Q The-lower rod 5 as viewed in the drawing'v has'a screw threadedv socket 11 opening .on .f thefend of the rod whichsocket receives the Fig. 1 4shows a plan'view of the instrument indicating its method of application Fig. 2 isa sideelevation vaccording to Fi 1; v

ig. 3 is a rear view with the back plate removed;

'F ig. 4 is a section on-the line 4-4fof 3;.1111'6 Fi ig. 5 is a section online 5-5 ofJFig.3.

Referring to the drawing I have shown .an indicator having a frame exemplified herein by a `casing 1 opposite sides of whichv are perforated and receivebushings 3 through whichy extend reciprocatory cylindrical cali-pering rods or arms 5. As ,1ndi cated the upper-rod -5 carries a removable end portion havinga calipering p oint 8,

' the end portieri for this purpose having the screw threaded stem 9 received in a screw threadedsocket in the end of the rod, andby this Construction I am able to employ end members 7 of different length s'o--a's to accommodate the' instrument to cylinders of various diameters, as is indicatedat 7 in Fig.

outerportion 13 of the rod, the outer porftion carrying 'the member 15 providing a -calipering point and also carrying ajknurl'ed'I head 1 7 by means of which the outer member may berotated for. screwing it more. or

`less into the socket 11 and thus adjusting the effective. length of the lowerfrod 5.

At its inner end each rod 5 'is iat one side thereof with rack teeth 19,- the rack teeth meshing with pinions 21 which aremounted on shafts 23 rotatably supported by the bracket 25 and the topplate I 27 of the casing. At the center of the top plate 27 is a pinion, 29in mesh with a pinion 31 carried by one ofthe shafts 23, the pinion' ldial and indicator-hand willbe moved, `the same direction,- and that vfor la relative provided- 29 having a hub 33 mounted inthe top plate 27. The' vhub 33 and pinion 29 areperf forated and rotatably receive a shaft 35 which shaft carries a pinion 37 and is supported at its innerv end `in the bracket 25.

Meshing with .the -pinion37 is a gearwheel 39 carried. on the u per shaft 23 as lvievved Y in the drawing. T e hub 33 of the pimon 5 carries a rotatabledial plate 41', while the carries a rotatableV indicator handy 43.

29 thusy driven by the -lower calipering rod.

' shaft 35 driven by the upper ca'lipering rod A As' illustrated-iny Fig. 4`thecalipering rods 5 carry arms 45 which at their outer'ends vengage a slot 47 formed in the bracket 49 secured .to the'topplate 27, this 'construction preventing rotation ofthe rods relatively to the othercasing.v Lost motionin thefgearwheels` is taken u'p`by the helical springs 53 which surroundl the shafts 23, the ear wheels for this purpose being splitrin. p anes transverse to the -axis'of the gears as shown in Fig. 4: and one lend ofthe springs.being .co nneoted to.' the adjacent vhalf ofi' the associatel gear and the other end of the. springs being 'cons l escribed nectedto a xed part ofthe casin It will be noted by the above constructionthat the cahperin'g rods 5 are movable relatively t'o each other and t the indicator casingand that: one rod causes rotation of the dial plate while thel other causes rotation of the vindicator hand.. It

will also be observed that when the rods movein the same direction, as for -example upwardly as viewed in the drawing, the

movement between the indicator hand and dial plate there must be' a relative movement between thecalipering rods 5, and fur-7 ther as wi1l be readilyV apparent the relative movement between the dial plate and indicator handris directlyproportional to the alegebraic difference 1n mp ion between the two rods. L

For placing the rods, on .the `cylinder `diameter to be -measured I provide'a support .in the lform of a plate having the base 55,

the end portions 57 of the base'being formed `at anfangle to the'body of the base so as to v present corners 59 for contactingthe walls' 110,*

rol

of the cylinder to be calipered. The casing 1 is secured by means of screws 63 tothe ton e 61 formed integrally with the plate 55. -.As will be observed by reference to Fig. 1 the corners 59 of the end portions 57 of the plate 55 rest on the cylinder walls at opposite i ends of a chord of the circle representing the transverse cross section 'of a cylinder whose diameter is to be measured, Vvvhile the calipering points at the ends of the rods are on a line which is normal to the chord and bisects the sameand as will be obvious by this means the caliperingpoints will always be centered on the diameter to be measured.

My instrument may be used in variousv ways, as for example it may be iirst tested With a set gauge, and while in the gauge the knurled head 17 can be rotated'v to cause the indicator needle to coincide with the zero point on the dial plate If the cali ering ,points are now moved from between t e set gauge and the instrument is applied to a cylinder vghose diameteris to be measured the readings will indicate the lamounts the diameter varies from the set gauge, the readings at one side of the zero point denoting oversizes and the readings at the other side of the zero point denoting undersizes. The graduations of the dial for this purpose may be calibrated in any convenient unit, as for example thousandths ofl an inch.

Although I have describedfor purposes of illustration one specific embodiment of my invention it is to be understood that within the scope of my invention wide deviations may be made therefrom without departing from the spirit of my invention.-

Claims: c

1. A calipering instrument, having in coinbination, a pair of caliper members, an indi- -cator comprising a frame, said indicator for yshowing the degree of separation of said vcaliper members, said caliper members each being independently movable v'relativelyto the other and to said frame :of said indicator for contact with opposedsurfaces, and actuating mechanism for' said indicator responsive to the algebraic difference in motion of said caliper members relatively to said rame. t

2. An instrument for calipering the internal' diameterof'cylindrical surfaces, having in combination, caliper members, means for engaging such surfaces and serving to posi-- tion said caliper members s0 as to contact diametrically opposite'v portions of4 such 4surlfaces an lindicator comprising a frame carried in ixed relation to said means, said indicator responsive to the position of said caliper members relatively to each other, said caliper members being independently movable relatively to each other and to said frame. l

3. An instrument for'calipering'the internal diameter of cylindrical surfaces, having in combination, a pair of caliper members, a support carrying said caliper members, said support having means for engaging points on such surfaces spaced transversely thereon for positioning said caliper members oli the diameters of such surfaces, an indicator comprising a frame carried by said support in fixed relation thereto, actuating means for said indicator operated by said caliper meinbers and responsive to the position bf said caliper members relatively to each other, said caliper members being independently movable relatively to each .other and to said frame. y e

4. An instrument for calipering the internal diameter of cylindrical surfaces, having in combination, a member having portions for positioning it on chords of the transverse sections of such surfaces, an indicator casing carried in fixed relation to said member, op-` positely positioned caliper members positioned in a plane normal to and bisecting said chords, said caliper members being independently movable relatively to the other and to said indicator casing for contact with opposed cylindrical Walls, and indicator mechanism in said casing responsive to the albebraio difference-in motion of said caliper members.

` 5. An instrument for calipering the inter.- nal diameter of cylindrical surfaces, having in combination, a member having portions for positioning it on chords of the transverse sections of such surfaces, an indicator casing carried in fixed relation to said member, oppositely positioned caliper members ppsitioned in a plane normal t0 and bisecting said chords, said caliper members being in'- dependently movable relatively to the other and to said indicator'casing, means for adjusting said indicator to a' predetermined reading when said calipermembers are in engagement with spaced surfaces, and indi-y cator mechanism in said casing responsive tothe algebraic difference in motion of said caliper'members relatively to said indicator casing.

6. An instrument for calipering the interi nal diameter of cylindrical surfaces, having 1n combination, a member having portions for positioning it on chords `of the transverse sections of such surfaces, an indicator casing carried in fixed relation to said member, oppositely positioned caliper memberspositioned in a plane normal to and bisecting said chords, said calipermembers being in dependently movable relatively to the other and to said indicator casing, 'one of said caliper members having relatively movable parts for adjusting the effectivelength of said` member, and indicator mechanism in` said casing responsive to the algebraic difference in motion of said caliper members relatively to said indica-tor.k

7. An instrument for calipering the interlac naldiameter of cylindrical surfaces, having in combination, a. member. having portions for positioning it on chorlds ofthetrans- 'verse sections ofsuch Surfaces, an indicator ing fin combination, a member having portions forpositioning it on chords o f the transverse sections of such surfaces, an ine i 'dicator casingl carried in fixed, relation to said member, rods carried 'by said member 1 and extending in opposite directions therefrom, said rods bein in a and bisecting said c ords.4

9. An instrumentfor. calipering the inplane normal to ternal diameter of cylindrical surfaces, havingv in l combination, -al member having .por- 4tions -or positioning it on chords of the transverse' sections of such surfaces, an'indicator casing carried' in ixed relation to -said member, rodsyextending from said member in opiposit'e directions, said rods vbelng indpen' ently movable relatively .to Y

the 'other and .to said member and lhaving calipering-pointslying in a plane normal to and bisecting said chords, 'and indicati'n kmechanism in said casing operated by sai rods and responsive to the algebraic difference in moti/on' of said rods relatively to said member.

cator casing carried in fixed relation to said member, krods vextending from said memberv 1n o posite directions, said rods being indepen ently movable relatively to the otherv and to said member and, having calipering points lying. in a plane normal to and. bi-

.seating said chords, the calipering pointv vof said rodadjacent said chord being -ad ljustable relatively to the body of said rod, and indicating mechanism in said casing T5 operatedby said rods and responsive to the algebraic difference in motion of said rods relatively to said 1nember.. v

12. A calipering instrument, having inl other and 'to said frame of said indicator,

and mechanism for causing equal motions of-sa1d lcahpermg lmembers 1n the same di- 90 rection to move'said graduated -member and pointer equal amounts inthe same direction and for causing relative motion between said calipering'members to move said graduated vI nember and pointer relatively to each other. 13. A- calipering instrument, having in combin ation,`a pair of caliper members, an indicator for showing. lthe degree of separation of said members, said' indicator having a frame supporting a dial platee m'ounted'for vangular motion and a'pointer' mounted for angular motion relatively to said dial plate, saidcaliper members independently movable. vrelatively to. the other and to said frame, and mechanism operated by one of said cali- .per members for angularly moving said dial-plate andby theother -caliper member ois - 10. An instrument for caliperingV the inf; for angularly moving said pointer.

ternal diameter of "cylindricalsnrfaces, hav- -ing in combination, a member" having l-tions for positioning it on vchords of the Atransverse sections of such surfaces,'an indicator casing carried in ixedfrelation to said member, frods extendingY from said member in oposite directions, said rods being` inde n`ent1y movablel relatively to the other and lto said member V"and. having ycali-.

in a ,plane-'normal to' 7 pering points lyin n zand bisecting sai chords, the calipermg point of one of said Irods being adjustable relatively to 'thebody of said rod, and indieating mechanism in said casing operated by said-'rods and 'responsiveto the algebraic di'erence in motion of said rods' relatively to said member. f

11.v An instrument Vfor caliperingl the-ina ternal diameter of cylindrical-surfaces, having in combination, a member' having por- .tions for positioningl it on chords of the vtransverse sections of such surfaces, an indi- 14. A calipering instrument4 having in combination, a pair of caliper members, an.

tion of said members,'said'indicator having av dial plate mounted for angular motion and af'pointer'mountedfjor angular' motion relatively to said dial plate, said caliper members independently movable lrelatively to the other and to said dial plate, and mechanism operated by said caliper members' tor' causing relative angular motion of said dlal plate and'point'er im proportion to the. algebraic difference motion of said callper members. f 'i- 15, A calip'erin-ginstrument, having in combination, a .dial plate mounted for angu' lar motion, atpo'inter cooperating with said 125 dial plate and mounted for-angular motion relatively to'said dial plate, a caliper -memberl operatively connected to said dial late for; moving'it a-ngularly, a second ca iper member operatively connected t0 saidpointer 110 indicator for showing the degree of separa- 16. A' 'calipe'ring instrument,` having in i combination, a dial .plate mounted for angular motion, a pointer cooperating with. said dial plate and-mounted for angular motion relatively to said dial plate, a pairof caliper members mounted for independent relative movement, mechanism connecting one of said caliper members to said 'dial plate for cansimg[motion of said caliper member toI move said'dial plate'langularly, a 'second mechan'ism connectin the other of said caliper members to sai pointer for causing motion of saidcaliper member -to move said pointer angularly, and. said mechanisms having means for. causing the .relative angular motion of said'dial plate and pointer to be pro-- portional to the relativemovement between said caliper members.

17. A lcaliperin'g instrument, having in combination, a movable dial plate and -a rela-f tively movable cooperating pointer independently movable calipering members, and mechanism actuated by said calipering members for causing relative motion between said dial plate and fpointer in proportion to the gisplacement between said calipering memers.

18. An instrument for calipering the internal diameter of cylindrical surfaces, having in combination, a support, a pair of op-` positely disposed caliperingV rods provided 'withl aligned calipering4 points, means for centering said calipering points with the diameters of such surfaces, a rotatable dial plate, a rotatable pointer. cooperating with said dial plate, a separate rack for each calipering member ,reciprocated thereby, and separate gearing of the same gearing ratio c onnecting one rack with said dial plate and the` other rack, with said pointer.

19. An .instrument for calipering the internal diameter of cylindrical surfaces, having in combination a support, a pair of op- 'positely disposed calipering rods provided with aligned calipering points means for adjusting the effective length of one of said calipering rods, means for centering said.

calipering points with the diameters of such surfaces, a rotatable dial plate, a rotatable pointer cooperating with said dial' plate, a separate rack for each calipering member reoiprocated thereby, and separate gearing of the same gearing ratio cnnecting one rack with said dial plate and the other rack with said pointer.

20. An instrument for calipering the internal diameter of cylindrical surfaces, having in combination, a support. having portions for contacting the opposite ends of chords of the transverse sections of such surfaces, an indicatorcasing fixed to said Support, oppositely projecting caliper rods exy tending from said casing and having ycalipering points on a. line normal to andbisecting said chords, said caliper rods being movablerelatively to each other and to said casing, a rotatable dial plate and a rotatable pointer for said dial plate carried by said casing, a pair of racks in said casing, one vrack of said pair being ieciprocated by one of said caliper rods and the other independently reciprocated by the other of said caliper rods, means for, changing the effective length of one of said caliper rods, and independent mechanisms connecting said racks Y respectively to said dial plate and pointer for rotating said dial plate and pointer, and said mechanism acting to cause relative rotation of said dial plate and pointer'in proportion tothe relative motion between said calipering points of said rods.

21.A calipering instrument *having in combination, an indicator, a pair of calipering members movable relatively to each other and to said indicator, mechanism responsive to motion of said calipering members for and said mechanism permitting bodily movement of said indicator relatively to both `calipering members While said caliperingv members are in contact vwith opposed. relacausing said indicator to indicate the degree of separation of said calipering members,

tively stationary surfaces without affecting pering members for causing said indicator to .indicate the degree of separation of said calipering members, and said mechanism. permitting bodily movement of'said indicator mechanism responsive to motion of said cali- 110 relatively to bo h of said calipering mem- 115 bers while said` alipering members are in contact with opposed relatively stationary said indicator. In testimony whereof, I naine to this speciication.

WARREN AMES.

Vsurfaces without aectinggthe reading of have signed my v120 

